topicsponge

Example code to log discovered sources and their source strings.

Table of contents

• topicsponge
• Table of contents
• Copyright And License
• Repository
• Introduction
    • Start Topicsponge First
    • Multiple TRDs
    • SRS
    • Limitations
• Configuring Topicsponge

Copyright And License

All of the documentation and software included in this and any other Informatica Ultra Messaging GitHub repository Copyright (C) Informatica, 2024. All rights reserved.

Permission is granted to licensees to use or alter this software for any purpose, including commercial applications, according to the terms laid out in the Software License Agreement.

This source code example is provided by Informatica for educational and evaluation purposes only.

THE SOFTWARE IS PROVIDED "AS IS" AND INFORMATICA DISCLAIMS ALL WARRANTIES EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. INFORMATICA DOES NOT WARRANT THAT USE OF THE SOFTWARE WILL BE UNINTERRUPTED OR ERROR-FREE. INFORMATICA SHALL NOT, UNDER ANY CIRCUMSTANCES, BE LIABLE TO LICENSEE FOR LOST PROFITS, CONSEQUENTIAL, INCIDENTAL, SPECIAL OR INDIRECT DAMAGES ARISING OUT OF OR RELATED TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREUNDER, EVEN IF INFORMATICA HAS BEEN APPRISED OF THE LIKELIHOOD OF SUCH DAMAGES.

Repository

See https://github.com/UltraMessaging/topicsponge for code and documentation.

Introduction

It can be useful keep track of which publishers create which sources. For publishers that create many sources, it can be useful to track which topics are mapped to which transport sessions.

The topicsponge program discovers UM sources and prints the topic and source string to standard out. It uses UM's resolver_source_notification_function callback to discover sources via topic resolution source advertisements.

The topicsponge program is intentionally written very simply to make it easy to be customized for a user's environment.

Start Topicsponge First

Depending on your applications' configurations, UM can stop advertising sources after a time. To get a complete list of sources, you'll have to start the topicsponge before the publishers are started. Ideally the topicsponge would be running continuously any time applications are running.

Multiple TRDs

In a network that has multiple topic resolution domains connected via DROs, the topicsponge will only reliably detect sources that originate in the same TRD as the topicsponge. The topicsponge can detect proxy sources creeated by the DRO on behalf of remote publishers, but only for topics that the DRO creates to satisfy subscribers. To get a complete picture of a UM network's sources, you should run a topicsponge in every TRD in the network.

SRS

In a TRD that is serviced by an SRS, the topicsponge should be configured with resolver_service_interest_mode (context) set to "flood".

Limitations

Note that topicsponge does not detect when a source is deleted or if the publisher exits. It cannot monitor for EOS or detect timeouts. However, automatic monitoring can monitor the liveness of transport sessions.

Configuring Topicsponge

In the interest of keeping the topicsponge's code simple, it does not load a configuration file. Instead, it relies on environment variables to specify a configuration file.

For example, for an XML-based config file:

export LBM_XML_CONFIG_APPNAME="topicsponge"
export LBM_XML_CONFIG_FILENAME="topicsponge.xml"
Linux64/topicsponge >topicsponge.log

Or for a "flat" config file:

export LBM_DEFAULT_CONFIG_FILE="topicsponge.cfg"
Linux64/topicsponge >topicsponge.log